Hearing aids are among the most demanding electronic devices on the market. They operate in a uniquely hostile environment – exposed daily to humidity, perspiration, skin oils and intermittent liquid ingress – all within an ever-shrinking form factor. As product miniaturisation accelerates and sustainability requirements tighten, manufacturers are under increasing pressure to deliver long-term reliability without compromising performance, repairability or cost structure.
At P2i, we take a solutions-led approach to this challenge. Rather than forcing a single technology into every application, we work with our customers’ Qualification Test Plans and CAD/STEP data to determine what level of protection is genuinely required, and which coating technology will deliver the best commercial and technical outcome.
The Corrosion Challenge in Modern Hearing Aids
The electronics within hearing aids – including PCBAs, interconnects, battery contacts and microphones – operate in a harsh, moisture-rich environment where sweat and salts can rapidly drive corrosion. As designs become more compact and geometrically complex, traditional protection methods such as liquid conformal coatings, gaskets, tapes and adhesives begin to show their limitations, adding thickness, constraining tolerances and complicating rework. Even thinner options like parylene can increase scrap and restrict serviceability. At the same time, manufacturers must align corrosion protection strategies with tightening environmental regulations and sustainability goals, including the move towards PFAS- and PFOA-free chemistries.
Splash-Proof Plasma Coating – PFOA-Free, Solvent-Free Protection
Our Splash-Proof plasma coating is PFOA-free – a significant milestone for manufacturers seeking environmentally responsible protection. It is applied using a dry, solvent-free plasma process containing no volatile organic compounds and no harmful wet chemistries.
Because the coating forms at a molecular level, it is ultra-thin – far thinner than gaskets, tapes or traditional liquid coatings. It fits everywhere without adding bulk or affecting tight mechanical tolerances. Critically, there is no change to microphone performance or audio quality, fully differentiating it from other coating technologies.
Splash-Proof technology prevents liquid ingress into the treated device under typical exposure conditions. It is ideally suited to protecting against splashes, light sprays and everyday perspiration while preserving the integrity and acoustic performance of the device.
Barrier Coating – PFAS-Free Corrosion Defence for Higher-Stress Environments
For applications requiring enhanced protection, our Barrier Coating provides PFAS-free corrosion defence – an increasingly important factor as the industry moves away from legacy fluorinated chemistries.
Barrier technology protects electronics even in scenarios that mimic IPx3-8 forces, such as stronger sprays, partial immersion or heavy sweating environments. In events where liquid is forced into the device, the coating prevents corrosion damage to the underlying board.
Like Splash-Proof, Barrier is delivered through a dry plasma process – with no nasty solvents, no volatile organics and no environmentally problematic substances. The result is robust corrosion protection that meets both reliability and regulatory requirements.
Repairability, Rework and Reduced E-Waste
Serviceability is essential in hearing aids, where batteries must be replaced, components repaired and e-waste minimised for both commercial and environmental reasons. Our plasma coatings support full repairability and rework, with precise masking and de-masking to protect selected PCBA areas while leaving connectors, test points and acoustic elements unaffected. Compared to parylene-coated devices, this approach can simplify assembly testing and reduce scrap, enabling durable protection in use without compromising in-market serviceability or sustainable product lifecycles.
A Pragmatic Option – Liquid-Based Coatings Where Appropriate
Many manufacturers already operate dip or spray nozzle systems for liquid-based conformal coatings. In some cases, the most operationally cost-efficient solution may be to optimise the chemistry within an existing setup.
As part of our solutions-led methodology, we can assess whether a revised liquid-based coating meets your performance requirements. This can represent the lowest entry point to protection.
However, where long-term reliability, environmental compliance and product differentiation are key drivers, Splash-Proof and Barrier plasma coatings typically provide superior performance. Their ultra-thin, solvent-free, PFOA-free and PFAS-free characteristics offer a clear technical advantage over traditional wet processes.
Proven Performance – Over 15 Years Supporting the Hearing Aid Industry
For more than a decade and a half, we have partnered with hearing aid manufacturers to engineer reliability into their products from the outset. Our work consistently delivers:
- Over 15 years’ experience delivering protective coating solutions to the hearing aid sector
- A consistent focus on reducing field-failure rates in real-world user environments
- Improved long-term reliability as device designs continue to evolve
- Fewer corrosion-related returns and lower warranty costs
- Reduced service interventions and improved operational efficiency
- Enhanced brand reputation through dependable product performance
- Molecular-level protection that translates into measurable downstream commercial benefits
Choosing the Right Protection for Your Device
There is no one-size-fits-all answer. The right solution depends on your product architecture, qualification criteria, environmental targets and cost structure.
By reviewing your Qualification Test Plan alongside your CAD or STEP files, our engineering team can recommend the coating that genuinely meets your requirements – whether that is Splash-Proof, Barrier or a tailored liquid-based solution within your existing process.
If you are developing the next generation of hearing aids and want to reduce field failures while meeting evolving environmental standards, we would be pleased to explore the right path forward with you. Get in touch to start the conversation.